Amid the relief and joy, there is something anticlimactic, almost numbing, as the American hostages begin to trickle home from Lebanon. In their absence, they have been with us so long.

Even the White House, it seems, has always been a bit distracted by some kind of Iranian problem, by liberation of one sort or another. In the very tumult of World War II, Franklin Roosevelt made his plans to reform a futile, impoverished Persia and to free the country from its historic predators, Britain and Russia. He was "thrilled by the idea of using Iran," F.D.R. once wrote his secretary of state, "as an example of what we could do by an unselfish American policy."

What a chasm separates that hope--Iran as an "example"--and the pathetic sight of thin-bearded figures, squinting and suddenly free of their blindfolds. Far from one President's distant dream, we have watched one of his successors, Jimmy Carter, brought down by policy turned tragic, by an Iran more enemy than example. And another, Ronald Reagan, nearly suffered the same fate.

So much ironic, largely hidden history trails our hostages out of their captivity. Roosevelt's altruistic vision died with him in 1945. The Soviets were held off from encroaching on northern Iran in one of the early checking moves of the Cold War, but the British and their ubiquitous oil interests promptly reappeared. By 1953, we had encountered our first troublesome Iranian leader, an eccentric, fiercely nationalist octogenarian named Mohammed Mossadegh, who was given to conducting diplomacy from his bed, often wept and fainted in the process, and in any case believed that Iran should own and control its own rich deposits of petroleum.

When negotiations failed--the first of so many--the CIA staged an elaborate and well-financed coup d'etat to replace Mossadegh with the young Shah Mohammed Reza Pahlavi and a more pliant regent-prime minister, Gen. Fazollah Zahedi, whose record included collaboration with the Nazis. In the aftermath, the British oil interests were secured, though not quite with the old monopoly. Five major U.S. oil companies divided 40% of the Iranian petroleum; another 20% was taken by Dutch and French firms.

Over the next quarter of a century, Washington was an ever-stronger supporter of the shah, our economic and mostly military aid growing from the hundreds of millions to more than $14 billion. Iran became a virtual American base in the Cold War, with several U.S. military installations and intelligence listening posts.